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INFLUENCE OF ELECTRICAL FIELDS AND ASYMMETRIC APPLICATION OF MUCILAGE ON CURVATURE OF PRIMARY ROOTS OF ZEA MAYS
Author(s) -
Marcum Heidi,
Moore Randy
Publication year - 1990
Publication title -
american journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.218
H-Index - 151
eISSN - 1537-2197
pISSN - 0002-9122
DOI - 10.1002/j.1537-2197.1990.tb13575.x
Subject(s) - mucilage , biology , zea mays , botany , curvature , gravitropism , agronomy , geometry , mathematics , biochemistry , arabidopsis , gene , mutant
Primary roots of Zea mays cv. Yellow Dent growing in an electric field curve towards the anode. Roots treated with EDTA and growing in electric field do not curve. When root cap mucilage is applied asymmetrically to tips of vertically‐oriented roots, the roots curve toward the mucilage. Roots treated with EDTA curve toward the side receiving mucilage and toward blocks containing 10 mm CaCl 2 , but not toward “empty” agar blocks or the cut surfaces of severed root tips. These results suggest that 1) free calcium (Ca) is necessary for root electrotropism, 2) mucilage contains effector(s) that induce gravitropiclike curvature, and 3) mucilage can replace gravitropic effectors chelated by EDTA. These results are consistent with the hypothesis that the downward movement of gravitropic effectors to the lower sides of tips of horizontally‐oriented roots occurs at least partially in the apoplast.